Register a currently running host to a new Rancher Server

Rancher 1.6.21 with Cattle on Linux.

Due to infrastructure issues I’ve lost the vm where were located my deleted rancher server.

I have running 4 hosts in another vms, I want to recover it registering to a new rancher server instance.

I did a test and if I delete the rancher agent and I try to register the running host to the new rancher server, all the previously up and running containers (there are some stacks added on the previous and deleted rancher server) are detected for a few moments as a “standalone containers” and after that are just deleted (that would be awful for my purposes).

It is possible to make the registration process without deleting the currently running containers on the host?